This section provides background information related to the present disclosure which is not necessarily prior art.
Modern automotive four-stroke internal combustion engine are typically configured with intake and exhaust valves that can be selectively opened via a valve operating system to intake air or an air-fuel mixture into the engine cylinders and to exhaust gasses from the engine cylinders. A valve operating system with a camshaft is commonly employed to control the timing and duration of the opening of the several valves. The camshaft typically includes several cam lobes, with each of the cam lobes having a shape that determines the duration that one or more associated valves are opened, as well as the amount by which the one or more associated valves are opened. It will be appreciated, too, that the position of an associated one of the cam lobes about the rotary axis of the camshaft determines the timing or phase of the opening of the one or more associated valves. The combination of the shape and phase of a cam lobe will be referred to herein as “cam profile”.
The operation of such internal combustion engines are greatly affected by the timing and duration of the opening of the intake valves and the exhaust valves and as such, it is known in the art to configure a camshaft with multiple sets of cam lobes that can be employed on an alternative basis to provide variable valve lift and/or variable valve timing. While such valve operating systems are suited for their intended purpose, they are nevertheless susceptible to improvement.